#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> Pr;
#define fi first
#define se second
#define mkp make_pair
#define pb emplace_back
// #define mid ((l+r)>>1)
#define popcnt __builtin_popcountll
const ll mod = 1e9+7;
inline ll read(){
	ll x=0, f=1; char ch=getchar();
	while(ch<'0' || ch>'9') { if(ch=='-') f=-1; ch=getchar(); }
	while(ch>='0' && ch<='9') x=x*10+ch-'0', ch=getchar();
	return x*f;
}
inline ll lg2(ll x){ return 63^__builtin_clzll(x); }
inline ll qpow(ll a,ll b){
	ll ans=1, base=a;
	while(b){
		if(b&1) ans=ans*base%mod;
		base=base*base%mod; b>>=1;
	}
	return ans;
}
void init(){ }
ll n,a[1005];
ll dp[1005], suf[1005], vis[75], pw[1005];
ll f[75][4][105];
map<ll,ll>mp;

void addmod(ll &x){ if(x >= mod) x -= mod; }
void procedure(){
	pw[0]=1;
	for(ll i=1;i<=1000;i++) pw[i]=pw[i-1]*2%mod;
	n=read();
	for(ll i=1;i<=n;i++) a[i]=read(), mp[a[i]]=i;
	for(ll i=n;i>=1;i--){
		for(ll j=a[i];j<=a[i]+74;j++){
			vis[j-a[i]] = mp[j];
		}
		memset(f, 0, sizeof(f));
		ll nxt = lower_bound(a+1, a+n+1, a[i]+75) - a;
		// cout<<"at "<<i<<" dping "<<endl;
		f[0][0][19] = 1;
		for(ll j=0; j<74; j++){
			for(ll k=0; k<=3; k++){
				for(ll l=0; l<=100; l++){
					if(!f[j][k][l]) continue;
					addmod(f[j+1][k][l] += f[j][k][l]);
					if(vis[j+1]){
						if(l>=j+1) 
							addmod(f[j+1][k][l] += f[j][k][l]);
						else if(k<3)
							addmod(f[j+1][k+1][j+20] += f[j][k][l]);
					}
				}
			}
		}
		// cout<<"at "<<i<<" dped "<<endl;
		for(ll k=0; k<=3; k++)
			for(ll l=0; l<=100; l++){
				if(f[74][k][l]){
					// cout<<"k = "<<k<<" l = "<<l<<endl;
					// cout<<"contri "<<(suf[nxt] + pw[n+1-nxt]*2*(min(2ll,k)+1)) <<" * "<<f[74][k][l]<<endl;
					dp[i] = (dp[i] + (suf[nxt] + pw[n+1-nxt]*2*(min(2ll,k)+1)) * f[74][k][l]) % mod;
				}
			}
		addmod(suf[i] = suf[i+1] + dp[i]);
	}
	printf("%lld\n", suf[1]);
}
int main(){
	#ifdef LOCAL
		assert(freopen("input.txt","r",stdin));
		assert(freopen("output.txt","w",stdout));
	#endif
	ll T=1;
	init();
	while(T--) procedure();
	return 0;
}